Colorectal cancer (CRC) is one of the most common cancer types in both men and women worldwide, with about 1.2 million new cases recorded annually. [1] The prognosis is highly dependent on the tumour stage at time of diagnosis. According to the American Joint Committee on Cancer (AJCC), the 5-year overall survival rate is 93%, 83%, 60% and 8% in stage I, II, III, and IV, respectively. [2] However, the prognosis for stage IIb patients (pT3-4, lymph node negative) is significantly lower (72%) than for those with stage IIIa (pT1-2, lymph node positive; 83%). [2]
Adjuvant chemotherapy significantly improves survival in among stage III CRC and is accepted as standard treatment of these patients. [3] The majority of stage II CRC patients are cured by surgery alone, but perforation of the tumour and few examined lymph nodes are associated with reduced survival, and are usually considered for adjuvant chemotherapy. A proportion of stage II patients without increased risk of relapse based on current clinical factors still develop relapse. One could consider treating all stage II CRC patients with adjuvant chemotherapy, but the effect of this has not been conclusive. [4-6]
This highlights the need for new biomarkers for more precise prediction of high-risk stage II patients, and consequently also improved individualized cancer care.